Check_MK is a complex addon for Nagios/Icinga and consists of three subprojects. The check and inventory system Check_MK is a general purpose Nagios plugin for retrieving data. It adopts a new approach for collecting data and obsoletes NRPE, check_by_ssh, NSClient, and check_snmp. It features a significant reduction of CPU use on the Nagios host and automatic inventory of items to be checked, and is especially useful with larger Nagios installations. "MK Livestatus" gives immediate and fast access to live and historic Nagios status data. It's a supported backend for many addons including NagVis, NagiosBP, and Thruk. "Check_MK Multisite" is a feature complete replacement for the Nagios GUI, and uses MK Livestatus as a backend. It is very fast, and supports efficient distributed monitoring.

NConf is a Web tool for configuring the Nagios monitoring software. It differs from similar tools by offering enterprise-class features like templates, dependencies, and the ability to configure a large-scale, distributed Nagios server topology. It lets you effortlessly maintain a distributed Nagios topology. It has a user-friendly GUI. It features host and service templates, a graphical dependency viewer, multiple authentication modes, a Nagios configuration importer, a CSV file importer, and a Perl database API. The data schema is customizable and expandable.

Adagios is a Web-based Nagios configuration interface built to be simple and intuitive in design, exposing less of the clutter under the hood of Nagios. It has a REST interface for both status and configuration data as well a feature complete status interface that can be used as an alternative to the Nagios Web interface.

check_openmanage is a plugin for Nagios that checks the hardware health of Dell servers running OpenManage Server Administrator (OMSA). The plugin can be used remotely with SNMP or locally with NRPE, check_by_ssh, or similar. It checks the health of the storage subsystem, power supplies, memory modules, temperature probes, etc., and gives an alert if any of the components are faulty or operate outside normal parameters.

Opsview Core is a network monitoring software application. It solves the challenges of monitoring modern IT and network systems. It is a drop-in replacement for Nagios Core, with full support for its plugins and 100% compatibility. It is easy to install and configure and is ideal for monitoring applications networks, and Windows, Linux, and Unix servers. VMWare, KVM, Xen, and Microsoft Hyper-V are supported, and Amazon EC2 and other cloud services can be monitored. It works with Opsview Mobile to allow you to monitor your systems on the go.

Jmx4Perl provides an alternate way of accessing Java JEE Server management interfaces that are based on JMX (Java Management Extensions). It is an agent-based approach where a small Web application deployed on the application server provides HTTP/JSON-based access to JMX MBeans registered within the application server. It is set up from a handful of Perl modules, which can be integrated seamlessly in your own programs. It also includes a Nagios plugin, check_jmx4perl, a jmx4perl command line tool for remote JMX queries and operations, and a readline-based JMX shell j4psh, with context sensitive command completion and syntax highlighting.

check_mysql_health is a plugin for the Shinken (Nagios) software that allows you to monitor a MySQL database. Among the list of metrics are time to login, index usage, bufferpool hit rate, query cache hit rate, slow queries, temp tables on disk, table cache hit rate, connected threads, and many more. Requirements are either a DBD::mysql Perl module or a MySQL client package.

OpMon is a network and system monitoring application based on Nagios with extended support for capacity planning, SLA, SLM, network discovery, service catalogs, report schedule, Davinci, a dashboard builder, and much more. OpMon provides a GUI for Nagios as well as full multi-language support. The license to use the opmon proprietary modules is free for 2 hosts and 20 services. OpMon comes with many open source applications like phplogcon, Nedi, ntop, nagtrap, OCSInventory, OTRS, and opcfg.

Shinken is an advanced monitoring system that is based on Nagios, but redesigned and rewritten from scratch while maintaining compatibility. It can monitor all IT devices from systems to end user applications. In case of a failure, Shinken can alert the operation engineers so they can promptly repair it. It has the same capabilities as Nagios along with more advanced built-in facilities such as load balanced and high availability monitoring.